Evaluation of Fungal Endophytes to induce Abiotic Stress tolerance in Wheat (Triticum aestivum)

Abstract

The stress caused due inanimate things is termed as abiotic stress which causes negative impact on the living organisms in a specific environment. At present abiotic stress is one of the leading causes of crop yield loss. The abiotic stress factors when occur in combination have the most detrimental impact on the plants. The rapid urbanisation and global hunger has lead to increase in the demand of food supply. Wheat being the most widely consumed staple food has always been the subject for yield improvement in order to meet the growing demand. The prevailing methods such as use of hybrid seeds, improving crop fertilizers etc., helped in yield improvement but there is a need of exploring a sustainable source for yield improvement. The diverse ecological niche of endophytic fungi has been of keen interest due to its symbiotic relationship with the host plant. These fungi have co-existed with the plants since ancient times and have shown potential in conferring stress tolerance to the host plants. In this study, endophytic fungi pre-isolated from different parts of two high yielding wheat varieties HD2967, WH1105 (grown in Punjab) were screened for abiotic stress tolerance. Two main abiotic stresses chosen were salinity and extreme temperature. The endophytic cultures were observed for growth till 10 days at different concentrations of NaCl (ranging from 5-20%) and temperature range (16C-40C). These were then compared with a control to screen out the best isolate that tolerates stress. The potent isolates #2(1)TAHRTU 12, #2(4)TAHLTU 15(e) and #2(1)TAWLTU 12(a) were subjected to production in potato dextrose broth for screening of its antioxidant activity. The isolate #2(1)TAWLTU 12(a) exhibited best antioxidant activity among the three. The total phenol content of the three isolates was also estimated in which isolate #2(1)TAWLTU 12(a) exhibited highest content of polyphenols and flavonoids. Further classical tools were used to identify the potent cultures; their genomic DNA was isolated and ITS region of approximately 500-600 bp was amplified before sending it for sequencing.